Kopff



2 Sheets-Sheet l.

Patented Mar. 14,1882

N4 PETERS, Pvwxmmwgnphnr. wahingwn. D. C.

(No Modvel.)

R. SGHWARTZKOPPP.

' SAFETY APPARATUS POR STEAM BOITIERS.

2 Sheets-Sheet 2.

(No Model.)

R. SGHWARTZKOPFF.

SAFETY APPARATUS TOR STEAM BOTLBRS.

No. 254,887. Patented Mar.14,1882

ib 55555545 ff $54554.T55551/175555ralf/$15.9515555515,ff/5.15 511551 N4PETERS, mmwuuwgmpmr. washingwn, D. Cv

UNITED` STATES PATENT OFFICE.

RICHARD SOHWABTZKOPFF, OF BERLIN, GER-MANY.

SAFETY APPARATUS FOR STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 254,887, dated March14, 1882,

Application tiled October 18, 1881.

(No model.) Patented in Germany August 10, 1880, and April 30, 1881, inFrance May l, 1881,

in Belgium May 4, 1881, in Great Britain May 5, 1881, and in AustriaJuly 4, 1881.

To all whom it may concern Be it known that I, RICHARD SCHWARTZ- KOPFF,of Berlin, Germany, engineer, have invented an Improved Safety Apparatusfor Steam -Boilers and for other Purposes, (for which l have received apatent in Germany August 10, 1880, No. 12,591 in Great Britain May 5,1881, No.1,953; in France May 4,1881, No. 142,670; in Belgium May 4,1881, No. 54,552, in Austria July 4, 1881, Tome XXI, folio 1,384, and anadditional patent in Germany April 30, 1881, No. 155634,) and of thisinvention the following is aspecitication.

The subject-matter of my invention consists in an apparatus by means ofwhich an electric current is established for the purpose ot' giving asignal, or of causing any other suitable ell'ect when the lowestadmissible water-level or a certain mmrimum temperature resulting eitherfrom an excess of pressure or from retarded ebullition occurs in asteam-boiler, the electric contact being made by the melting of aneasily-fusible metal. The apparatus may, however, also be used forcontrolling temperatures in other cases,and,in a somewhat modied form,even such temperatures as are below the point of fusion ot' metallicalloys. This apparatus is represented on the annexed two sheets ofdrawings.

Figure 1 is a vertical section of the apparatus arranged for controllingthe temperature as well as the water-level in a steam-boiler. Fig. 2shows a modification ot' parts thereof. Fig. 3 is a simpliledarrangement adapted to indicatea certain maximum oftemperature not beingbelow the point of fusion of metallic alloys. Fig. 4 represents amodification of the latter arrangement applicable for temperatures lowerthan the foregoing. Figs.5 and 6 are respectively an outside view and avertical section of the upper portion of a modification of the firstarrangement.

The apparatus represented by Fi g.1 consists of two metal tubes, c andf,ot' different diameter, the narrower tube, e, being insertedconcentrically into the wider tube,f. Both tubes are so connectedtogether at their upper end that the annular space between them ishermetically closed at the top, whereas the inside tube, e, which shouldproject with its lower end from the outside tube, f, is closed at `thebottom. rllhe tubcfis fixed in such a manner in the crown ot' the boilerthat its lower edge is at the height ot' thelowestadmissible waterlevel,L W. Its length outside of the boiler must be such as to allow its upperend to remain comparatively cool, four l'eet heilig ordinarilysufficient for this purpose. lithin the inside tube, @,there are twoinsulated conducting-wires or thin rods, a a., by preference of copper,which carry two cups or hcllow disks, I) and b, of porcelain or othersuitable insulating material, the cup b being near the bottom of thetube and the cup b near its top. Each of these cups is placed in a metalring, 7;, somewhat longer than the cup, so as to form a projecting rimofthe same. rlhe wires traverse the upper cup and pass into thelowerone, which is tixed to their ends. For the purpose of preventingthe wires from touching each other and thetube e, they arecoudnctedthrough a cylinder, d, and a plug, d', made ot wood or other insulatingmaterial. Instead of this cylinder d, a number ot' insulating diskssuoli as shown in Fig. 6, together with a short plug similar to the plugd', may, however, be applied. The outer end ot the wires a a isconnected by means of other wires with an electric battery and anelectro-magnet, which may be used for operating an alarm-bell or othersignaling device, or an arrangement for eX- tinguishing the (ire ordroppingthegrate-bars, Src.

Into the metal rings 7:, forming the rims of the cups or disks b and b',are placed the rings c and c, respectively, made ot' an easilyfusiblemetal or alloy. The pointot' fusion ot' the lower ring, o, should beslightly higher than the temperature which the water in the boiler hasat the maximum degree ot'steam-pressure allowed, whereas the upper ring,c', must melt by the heat of the steam when at its lowest pressure.These rings are made to tit closely to the rim 7o in order to preventtheir outer surface from being oxidized. On the inside they may besimilarly protected bythe end ot' the cylinder d and ot' the plug d. ltis, however, not absolutely necessary that the rings annular shape, maybe employed.

c and c be constructed exactly as described. Their form and arrangementmay he modified, and even a fusible metallic body, not heilig of Also,the wires a a may be insulated in a different man ner.

The action of the apparatus is as follows: While the water-level in theboiler is higher than the lower edge otl the tubef water will be pressedby the steam into the annular space between the two tubes as far up asthe air contained in this space permits. apparatus outside of the boilerbeing sufficiently long, the surrounding air will keep the temperatureof' its top end considerably below the temperature of the steam when atits lowest degree oi" pressure. Under normal circumstances the upperring, c', whose point ot' fusion may be, for instance, at 000centigrade, (1940 Fahrenheit,) will therefore not melt; but when thewater-level sinks below thelower edge ofthe tube/'steam will enter intothe annular space between c andf, and by its heat melt the ring. Themolten metal t'lows into the cavity hot' the cup and produces contactbetween the two wires a a, whereby the electric apparatus is put intooperation. lVhen, on the other hand,thesteam-pressure,and consequentlythe temperature ot' the water, become excessive, the lower ring, c, willmelt and cause the electric contact between the wires a a in a similarmanner as in the rst case. The same ei'ect is produced by an excess oftemperature caused by retarded ebullition.

In order to prevent bubbles of steam from entering into the annularspace between the two tubes during the regular working of the boiler,the projecting part of the tube e may be provided with a collar, m,which directs these bubbles sidewise.

It the apparatus is to be used for controlling the height ot'water-level only, the cup b and the ring c are left away; but thetubecshould not be made shorter, as otherwise the water would iill outthe whole area of the tubef, which might cause a prejudicial heating ofthe upper' part of the apparatus. Vhen a fusion otl either of the ringsc or c has taken place 'the wires, together with the cups, dac., arewithdrawn from the tube c, the metal which had been melted is removedfrom the cup, and a new fusible ring is introduced.

rlhe conducting` wires or rods a a may be made in sections jointed orscrewed together, as shown in Fig. 2, whereby their insertion into andwithdrawal from the apparatus are facilitated when there is but littleroom above the boiler.

XVhen a maximum degree of temperature only is to be indicated the upperpart ot the apparatus, with ring cf, cup L', &c., and also the tube f,may beleft away, or the apparatus represented by Fig. 3 may be used. Inthis modification the tube c is inverted, the cup b is placed on top ofthe insulating-cylinder d, or the ripper end of this cylinder forms thecup,

rlhe part of the while the fusible metallic body c is made in the shapeot'a disk pressed by the top edges ot' the cylinder d (or of the cup b)against the top et' the tube c. 'lhe apparatus arranged in this form isintroduced from below orobliquely from the side into the vessel, thecontents of which are to be controlled with regard to their temperature.If this temperature is to be maintained below the degree ot' heat atwhich easily-fusible alloys melt, the arrangement shown by Fig. 4 willbe found available. The electric contact between the two wires u. a isin this case obtained by a metallic plug, c, which is kept suspendedabove the ends ot' the wires by means ot' tallow, wax, parat'line,stearine, or any othereasily-fusible substance, such sub stance heiligpoured in melted state or pressed into the cavity It ofthe cup b andinto the groove with which the plug 0" is provided. When the tallow,tvc.. in h becomes sul'lciently 'soft troni an excess ot' temperatureabove the degree desired theplug cdcscendsand causes contact between theconducting-wires.

In thearrangementofapparatusrepresented by Figs. 5 and G the tube j" isdivided into two parts, the upper one of which is liernieticallyattached to the tube c at the top as well as at the bottom, whereas thelower partis thus fixed atthe top only. lThe two parts ot' j" are put incommunication with each other by a comparatively narrow pipe, Z, whichis bent spirally or in other suitable manner, so as to allow a certainlength to be condensed into a small space. This pipe, presenting aconsidcrable cooling-surface for the water which enters into the same,admits a reduction ot' the total length ot' the apparatus outside ot'the boiler.

Vhen in any works two or more boilers are provided with the controllingapparatus all these apparatuses maybe put in relation with the samealarm-bell, provided that a small electro-magnet be inserted into cachcircuit previous to its connection with the other conducting-wires. thepower ot' this electro-magnet being utilized for indicating the numberor other 'designation of the controlling apparatus by which the currenthas been established. As in other arrangements of this kind, theelectro-magnet may, for instance, be employed for opening a hinged platewhich covers the number, the., arranged together with the other numberson a register-board.

The described apparatus presents the advantage that it is not subject tosuch inconveniences as often occur with the safety apparatuses atpresent applied to steam-boilers. It is not liable to become inoperativeor to stick, as is often the case with steam-gages, iioats, andsafety-valves. Its fusible rings are notexposed to incrustation, as theordinary fusible plugs, and its action does not give rise to any esca-peot' steam. It is, on the contrary, always in a state to indicate withcertainty and in due time all causes ot danger ot' an explosion,including the retarded ebullition, for the IOO IIO

IIS

indication ot' which no appropriate instrument has heretofore been inexistence.

I claim as of my inventionl. The combination, within a tube, c, ot' aninsulating-cup, b, of two insulated conductingwires, a a, connected withan electric alarm-bell or other electric receiver and passing into thesaid cup, and of a metallic body so arranged with regard to the wires ac that it will cause contact between them either by its own fusion or bythe fusion of tallow, wax, paraftne, stearine, or any other4easily-fusible substance by which the said metallic body is keptsuspended, substantially' as and Jfor the purpose described.

2. The combination, with the tube c, coiltaining in its upper part theinsulating-cup b', the two insulated conducting-wires a c, c'onnectedwith an electric alarm-bell or other receiver and passing into the saidcup, and the easily-fusible metallic ring or body e', arranged asdescribed, ot the tube f,` surrounding the tube e and hermcticallyattached to the saine at the top, as hereinbefore described, and for thepurpose spe ited.

3. The combination, with the tubes e andf and the two conducting-wires ca, of the two insulating-cups b and b and the two easilyfusible metallicrings or bodies c and c, the wires c a., passing into or through the cupb and into the cup b, substantially as described, and for the purposestated.

4. The combination7 with the tube e, containing the cups b and b', theconducting-wires c c and the fusible metallic rings or bodies c and c',and with the tubef, made of two parts, of the pipe l., as hereinbet'oredescribed, and for the purpose specih'ed.

5. The combination, with the tube c, surrounded by the tubef and'containing the described parts a a, I) b', c, and c', ofthe collar m,as and for the purpose stated.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

RICHARD SCIIWARTZKOPF F.

Witnesses:

BnnTHoLD ROI, CARL NEUER.

